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The cut-and-leave method was first recommended by the Texas
Forest Service for controlling small spots (10 to 50 infested trees) that
could not be salvaged. This technique involves felling infested trees and a
buffer of uninfested trees and leaving them in the woods. The treatment
disrupts spot growth and causes emerging adults to disperse into the
surrounding forest. Cut-and-leave should be used during the period when SPB
spots are expanding (approximately May to October). Spots should be treated
only if they contain trees with fresh attacks. The method has been primarily
used in the Gulf coast States.
Cut-and-leave is practical, relatively inexpensive, and
requires a minimum of manpower, equipment, and training. The procedure can
be applied soon after spots are detected. The major disadvantage is that a
buffer strip of green uninfested trees must be felled around each spot to
assure that newly attacked trees, which favor spot growth, are included in
the treatment. If salvage becomes feasible at a later date, though , the
felled trees can be removed. larger spots (51-150 trees) can be treated
using the cut-and-leave method if the spots will eventually be salvaged.
Procedures for Cut-and-Leave
- Select spots with 10 to 50 infested trees. Some must have
fresh attacks. Higher priority spots, those with a high proportion of
newly attacked trees, should be treated first. Spots with more than 50
currently infested trees can be treated if they are to be salvaged
later.
- Mark and fell SPB-infested trees toward the center of the
spot.
- Mark and fell a horseshoe-shaped buffer strip of green
uninfested trees around the trees with fresh attacks. Fell them toward
the center of the spot. In small spots the buffer may encircle the spot.
However, the buffer should be no wider than the average height of the
trees in the spot.
- Dead trees from which all SPB have emerged need not be
felled. Leaving these trees will allow the beetle's natural enemies to
complete their development and emerge. Such trees also provide nest
sites for certain woodpecker species.
- Check cut-and-leave spots for breakouts during the next
aerial survey. Treat breakouts as needed.
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